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X-Pump Block for heating an entire house.

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Hey there, guys:

I've been asked by an architect to design a heating system; in-slab radiant downstairs, Warmboard or some such thing upstairs. Heatloss numbers are low: 25,000 BTU's on a design day. The Taco engineering says no problem, but I've never used a Taco X-Pump block for an entire house, only on small additions.

The water heater hasn't been decided on yet, but it would be something with enough capacity for the radiant.

Any experience out there?
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab

Comments

  • solradman
    solradman Member Posts: 58
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    Lots of less than 1500 sq ft places, biggest house we have with a single x block in is 2200 sq ft. Installed Oct of last year. House had non-barrier radiant tubing with light weight over pour and tile and wood floors. Heat loss close to 33,000 Btu's. Located about an hour south of Seattle. Talked to them last week and they said they had know problems with the cold month we just had with temperatures below freezing. It would be cool if they made it with a variable pressure pump on the radiant side.
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,646
    edited February 2017
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    I've done a 2,200 square foot house slab on an XPB-1. Had glycol in slab because owner was paranoid of freezing...

    Ran 12" tube spacing with 290-320' 1/2 barrier pex. Had no issues, was high temperature boiler though.

    I'd be tempted to build my own as their FPHX is small, the control is a Tekmar. Two circs an injection controller, and FPHX is what your buying.
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • Alan (California Radiant) Forbes
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    Thanks, guys!

    I don't mind buying one off the shelf because it's a real space saver.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Zman
    Zman Member Posts: 7,574
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    I think it is going to come down to how many gpm you need on the radiant side.the taco x block does not have tons of capacity on that side.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • hot_rod
    hot_rod Member Posts: 22,254
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    Zman said:

    I think it is going to come down to how many gpm you need on the radiant side.the taco x block does not have tons of capacity on that side.

    Flow rate and delta T between A & B side (approach temperature) would be the way to determine the capacity. Taco should have the HX performance spec, or look up a similarly sized one at the free online HX sizers like flatplate select.com
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Zman
    Zman Member Posts: 7,574
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    They do have a pump curve in the installation instructions that accounts for exchanger head loss.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein